Process of making hollow soldered cable and curb chains and ring-plattings of precious metal.



. F. MAISENBACHER. PROCESS OF MAKING HOLLOW SOLDERED CABLE AND CURB CHAINS AND RING PLATTINGS 0F PRECIOUS METAL.

APPLICATION FILED AUG-6, I913.

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Patented July 6, 1915.

WTTED @TATES PATENT @FFTQE.

FRITZ MAISENBAGHER, OF PFORZHEIM, GERMANY.-

PROCESS OF MAKING HOLLOW SOLDERED CABLEE A1\TD CUR-B CHAINS AND BING- PLATTINGS OF PRECIOUS METAL.

Specification of Letters Patent.

Patented July 6, 1915.

Application filed August 6, 1913. Serial No. 783,421.

To all whom it may concern.

Be it known that I, Fnrrz MAISENBAOHER, a subject of the German Emperor, andresident of Pforzheim, Germany, have invented certain new and useful Improvements in Processes of Making Hollow Soldered Cable and ourb Chains and Ring-Plattings of Precious Metal, of which the following is a specification. i

In the manufacture of jewelry, most of the precious metal chains are made hollow for economic reasons, as such of solid precious metal are of course'rather expensive. Hollow chains could, however, hitherto be made by hand only, and that of rather strong wires. For, hollow wire cannot be bent without losing its shape, for which reason it must be provided with a core of base metal. Thus, it was necessary to coat a wire of iron, brass or other base material with a thin strip of precious metal, so that on the whole core a uniform open longitudinal seam of a certain extent was left. This seam has the purpose to allow the entrance of the acid, which effects the dissolution and removal of the inner wire after formation of the chain links. The wire thus prepared is then wound in a spiral fashion on a round, oval or similarly shaped spindle, of which the cross-section corresponds to the inner width of the chain links to be formed, the longitudinal slot being always placed by hand upon the spindle. Thereupon, this spiral is sawed open in longitudinal direction, so that it is divided into single rings with oppositely directed ends. These rings are, by hand, entangledto form chains, of which the joints are singly soldered and which may be converted by twisting into curb chains. The chain thus prepared is then boiled in an acid dissolving the inner core, so that the empty hollow links only are left.

The present invention, which is hereinafter described and illustrated in the accompanying drawing, replaces the whole hand-work by a mechanical process.

Figure 1 is an elevation of a machine used in connection with the process, while Figs. 2 and 3 show, on a larger scale, elevations of the wires prepared for this purpose.

On a wire of iron, brass or other base metal, a seamless cylindric shell of precious metal is welded or drawn in a way known in the art, whereupon the wire is straightened and introduced, by means of the reciprocating slide 6, into the machine, first into the carrier a, of which the very narrow wire guide secures an advance of the wire in straight direction without lateral turning. The slide f, which moves behind the cutter d by operation of a lever 2', presses in its position of rest, by means of screws 6, 6', against the upper jaws 72., It, which are adjustable in their position of height on the pins 9, g, and arrest the wire in its position. Thereupon, the cutter cl, which is guided between the screws 6, e, in a slot'of the plate is, descends and cuts a longitudinalslot or opening (Fig. 2) into the outershell of the wire exactly at the highest line' of its circumference. The cutter may have a horizontal, oblique or round cutting edge. In case of a solder-cored wire being employed, the openings must not be too deep in order not to reach to the soldercore but to the base metal layer only inserted in this case between the solder-core and the outer shell of precious metal, as.

otherwise, if the openings would also be cut in said base metal layer, when soldering the liquid solder would penetrate the openings and again close the same entirely, so that the intended object is not obtained. The longitudinal slot remains during the further movement of the wire through the slide 6 always upwardly directed and receives thus upon the formation of the link its place at the inner circumference of the closed chain link. The length of the longitudinal slot is preferably somewhat shorter than each advance of the wire, it being so located in the precious metal shell that it lies exactly in the middle between the two cut-offends of the wire, which cutting-off is effected by the cutter n. The longitudinal slot does thus not extend over the whole length of the link wire but to a short distance from both ends only, so that the cross-sections at these ends of the shell remain closed. The wire thus prepared is then led beneath the cutter n toward the abutment 0 and formed in a way known in the art into links, which are closed by the joiner g. The soldering of the chain is effected automatically in any appropriate way. The chain is then, as in the above-described hand-operated process, exposed to the action of hot acid, which penetrates the interior of the links through the longitudinal slot therein, and, if necessary,

agitated in this bath by a mechanical contrivance in order to accelerate the dissolving process of the base metal core. This will, however, hardly be necessary, for since the acid can enter the slot from above and leave the same at the bottom and this circulation happens automatically owing to the Weight of the acid increasing with the metal dissolution, the latter is effected in a few hours Without assistance by hand.

The longitudinal slot, Which extends almost over the Whole length of the link, can be replaced by a plurality of openings (Fig. 3) arranged at equal distances from each other in a straight line.

What I claim is:

1. In a process of making hollow soldered cable, curb and other chains and ring plattings of precious metal from a Wire consisting of a core of base metal With a seamless precious metal shell drawn or Welded upon the same, successively advancing the Wire, providing the latter at those places,

Which upon formation of links assume the innermost position therein, With openings,

and forming then. links from the Wire, substantially as and for the purpose set forth.

2!. in a process of the kind described, providing core of base metal With a seamless precious metal shell drawn or Welded upon the same and cutting, sawing, shaping or boring into the latter at those places, which upon formation of links assume the innermost position therein, and between the ends of the links to be fomed short openings, While leaving the ends of the links uncut by said openings, substantially as and for the purpose set forth.

In testimony whereof I have hereunto set my hand in the presence of two subscribing Witnesses.

FRITZ MAISENBACHER.

Witnesses JOSEPH Prnrrrnn, VVILHELMINE BECKER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

